content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.flowable.internal.operators;
  
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicLong;
  
  import org.reactivestreams.*;
  
  import hu.akarnokd.reactivestreams.extensions.RelaxedSubscriber;
  import io.reactivex.common.*;
  import io.reactivex.common.Scheduler.Worker;
  import io.reactivex.common.exceptions.MissingBackpressureException;
  import io.reactivex.common.internal.disposables.SequentialDisposable;
  import io.reactivex.flowable.Flowable;
  import io.reactivex.flowable.internal.subscriptions.SubscriptionHelper;
  import io.reactivex.flowable.internal.utils.BackpressureHelper;
  import io.reactivex.flowable.subscribers.SerializedSubscriber;
  
  public final class FlowableThrottleFirstTimed<T> extends AbstractFlowableWithUpstream<T, T> {
      final long timeout;
      final TimeUnit unit;
      final Scheduler scheduler;
  
      public FlowableThrottleFirstTimed(Flowable<T> source, long timeout, TimeUnit unit, Scheduler scheduler) {
          super(source);
          this.timeout = timeout;
          this.unit = unit;
          this.scheduler = scheduler;
      }
  
      @Override
      protected void subscribeActual(Subscriber<? super T> s) {
          source.subscribe(new DebounceTimedSubscriber<T>(
                  new SerializedSubscriber<T>(s),
                  timeout, unit, scheduler.createWorker()));
      }
  
      static final class DebounceTimedSubscriber<T>
      extends AtomicLong
      implements RelaxedSubscriber<T>, Subscription, Runnable {
  
          private static final long serialVersionUID = -9102637559663639004L;
          final Subscriber<? super T> actual;
          final long timeout;
          final TimeUnit unit;
          final Scheduler.Worker worker;
  
          Subscription s;
  
          final SequentialDisposable timer = new SequentialDisposable();
  
          volatile boolean gate;
  
          boolean done;
  
          DebounceTimedSubscriber(Subscriber<? super T> actual, long timeout, TimeUnit unit, Worker worker) {
              this.actual = actual;
              this.timeout = timeout;
              this.unit = unit;
              this.worker = worker;
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              if (SubscriptionHelper.validate(this.s, s)) {
                  this.s = s;
                  actual.onSubscribe(this);
                  s.request(Long.MAX_VALUE);
              }
          }
  
          @Override
          public void onNext(T t) {
              if (done) {
                  return;
              }
  
              if (!gate) {
                  gate = true;
                  long r = get();
                  if (r != 0L) {
                      actual.onNext(t);
                      BackpressureHelper.produced(this, 1);
                  } else {
                      done = true;
                      cancel();
                      actual.onError(new MissingBackpressureException("Could not deliver value due to lack of requests"));
                      return;
                  }
  
                  Disposable d = timer.get();
                  if (d != null) {
                      d.dispose();
                  }
  
                  timer.replace(worker.schedule(this, timeout, unit));
              }
  
  
          }
  
          @Override
          public void run() {
              gate = false;
          }
  
          @Override
          public void onError(Throwable t) {
              if (done) {
                  RxJavaCommonPlugins.onError(t);
                  return;
              }
              done = true;
              actual.onError(t);
              worker.dispose();
          }
  
          @Override
          public void onComplete() {
              if (done) {
                  return;
              }
              done = true;
              actual.onComplete();
              worker.dispose();
          }
  
          @Override
          public void request(long n) {
              if (SubscriptionHelper.validate(n)) {
                  BackpressureHelper.add(this, n);
              }
          }
  
          @Override
          public void cancel() {
              s.cancel();
              worker.dispose();
          }
      }
  }
  